Recovery of sulfur from sulfur-bearing gases.



No. 878,569..' PATENTED FEB. 11, 1908.

P. 3. SMITH.

RECOVERY OF SULFUR PROM SULFUR BEARING GASES. APPLIGATION FILED MAY 25, 1907.

UNITEDSTATES PATENT oF roE PA l'L s. SMITH,

OF WILMINGTON, DELAWARE, ASSIG NOR TO THE E. I. DU PONT DE NEMOURS POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF NEW JERSEY.

RECOVERY OF SULFUR FROM SULFUR-BEARING GASES.

Specification of Letters Patent.

Patented Feb. 11, 1908.

Application filed May 25. 1907. Serial No. 375.597.

the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification.

My invention has'for its ob'ect to recover sulfur from kiln gases or smelter gases, and to this end, my invention consists in causing the sulfur dioxid separated from said gases to react with water gas, thereby reducing the sulfur dioxid to sulfur vapr, which is afterward condensed.-

In the drawings, the figure is a'diagrammatic view of'an apparatus adapted for the carrying out of my process. The mixture of gases containing sulfurous oxid is led by the pi e a to the tower b, which is filled with 00 e, pumice, or other suitable material, which is continually mois tened by a downward stream of Water. In their upward passage through the tower, the gases are washed, free of theircontent of sulfurous acid, which collects in aqueous solution at the bottom of the tower, the gases insoluble in water escaping by the pipe 0.

The aqueous solution of sulfuric: oxid obtained in the manner described above, flows throu h the pipe d to vessel e, where it is heate by the steam coil f, or other suitable source of heat, the reater part of the dis-. solved sulfu-rous oxi bein evolved in consequence. The gaseous su rous oxid thus produced, together with a certain amount of aqueous vapor, is conducted by the ipe g to the condenser h immersed in cold water. The greater part of the aqueous vapor having condensed in the condenser h, the sulfurous oxid gas passes by the pipe '11 to the dryin tower j, filled with lumps of calcium ch orid or other suitable dehydrating material,'whereby'the last traces of moisture are absorbed, the dry sulfurous oxid passing by the pipe k to the reducer l, which consists of a fire clay retort filled with fire brick checker-work, the retort being so arranged in the furnace m as to be heated to a high temperature in a manner to be described.

The last traces of sulfurous oxid are not expelled'from the water in the vessel 0 by heating, and moreover, the water condensed in the condenser h, absorbs a certain amount tact. To expel these last traces of sulfurous oxid, the partially exhausted water in the vessel e and the water condensed in the condenser h, flow by the pipes 0 and n respectively to the tower p, filled with lead wire net-work, through which water descends in the form of rain or mist. Steam is introduced by the pipe 9, and, passing upward through the tower, deprives the descending water of the last traces of sulfurous oxid,

which, together with a certain amount of steam, passes by the pipes 1' and,g to the condenser h. The spent water from the tower escapes by the pipe 8.

For the purpose of carrying out my process more economically, a gas roducer is used as a part of the apparatus, t e same being designated by t in the drawing. It has of the sulfurous oxid with which it is in conbeen stated that the reducer Z is necessarily highly heated during the process, and for this purpose the producer gas necessarily formed by the air-blast introduced throu h the pipe u'for the urpose of brin ing t e coal in the gas pro ucer to the con ition of incandescence essential to the production of water gas, is led from the producer t through the pipe 1) to the producer-gas-holder w, and thence is allowed to pass, as re uired, through the pipe as to the burner y, w ere it is burned with the assistance of an air-blast introduced through the pipe 2, for the purpose of heatingl the retort Z. t

10 is a pipe, eadin from a source of steam supply through whic steam is admittedto' the producer after the coal therein is heated to incandescence, duce water-gas. The water gas so enerated is led by the pipe 11 to the asolder 12, from which it is conducted by t e ipe 13 to the retort Z, where it effects the re uction of-the sulfurous oxid introduced by the pipe 7c, as. described. The sulfur vapor,water, and carbon dioxid formed in the retort Z by the interaction of the sulfurous oxid and water gas, pass to the condensers 14, 15 and 16, where the sulfur and water condense, the carbon dioxid escaping by the pipe 17.

The reaction in pressed as follows Which of the two above reactions occurs depends upon the temperatureat which the wateras is formed. When the water-gas is forme at a tempertaure above approximately 1000 0., CO+H 'is formed. When water-gas is formed at a temperature below approximately 1000 0., CO +2H is formed. In practically carrying out my process, a mixture of these gases will ordinarily be formed and led to the reducer.

Having now fully described my invention, What I claim and desire to protect by Letters Patent is:

1. The process of recoveri sulfur from gases containing sulfur dioxi which consists in first separating therefrom sulfur dioxid, then bringing the sulfur dioxid in contact with water gas and highly heating the the reducer may be ex- I mixed gases whereby the sulfur dioxid is reduced to sulfur, and then condensing the sulfur, substantially as described.

2. The process of recovering sulfur from gases containing sulfur dioxid which consists 1n first separating sulfur dioxid from the mixed gases, then causing the sulfur dioxid to react with Water gas to reduce the sulfur dioxid to sulfur, and then" condensing the sulfur, substantially as described.

3. The process of recovering sulfur from sulfur dioxid-which consists in successively formi producer gas and water gas, mixing the su dioxid and water gas, heating said mixed gases by means of the producer gas, thereby causing the mixed gases to react with evolution of sulfur vapor, and then condensing the sulfur, substantially as described;

In testimony of which invention, I have hereunto set my hand, at Wilmington, Del., on this 21st dayof May, 1907.

PAUL s. SMITH.

Witnesses:

JAMES J. 000K, IRVING EYER. 

